4C Tool Hub

Mortgage Calculator

Estimate your monthly mortgage payment — including property tax and insurance — and see exactly how much interest you'll pay over the life of the loan.

20% down
Total monthly payment
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Principal & interest
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Tax + insurance / mo
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Total interest paid
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Total cost of loan
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How your mortgage payment is calculated

Your monthly principal-and-interest payment uses the standard amortization formula: M = P × r ÷ (1 − (1 + r)−n), where P is the loan amount (price minus down payment), r is the monthly interest rate, and n is the number of monthly payments. Early payments are mostly interest; over time, an increasing share goes to principal — the schedule above shows that shift year by year.

What lenders look at

Most lenders want your total housing cost (payment, tax, insurance, and heating) below roughly 28–32% of gross monthly income, and total debt payments below about 36–44%. A 20% down payment typically lets you avoid mortgage default insurance (CMHC in Canada, PMI in the US), which otherwise adds to your monthly cost.

Tips that save real money

  • Shorter term: a 20-year term instead of 30 dramatically cuts total interest, at the cost of a higher monthly payment.
  • Rate shopping: even 0.25% off the rate on a $400,000 loan saves roughly $20,000+ over 25 years.
  • Extra payments: most mortgages allow annual prepayments that go 100% to principal.

Frequently asked questions

Does this calculator work for Canadian and US mortgages?
Yes, with a caveat: this calculator uses monthly compounding, the US convention. Canadian fixed-rate mortgages compound semi-annually, which makes the true payment slightly lower at the same quoted rate — typically a difference of a few dollars per month. Use it for planning, then confirm exact figures with your lender.
What's included in the "total monthly payment"?
Principal, interest, plus your annual property tax and home insurance divided by 12. It does not include utilities, condo/HOA fees, or mortgage default insurance premiums.
How much down payment do I need?
In Canada: at least 5% on the first $500k (20% to avoid CMHC insurance). In the US: conventional loans often allow 3–5% down, with PMI required below 20%. More down payment means a smaller loan and less interest.
Should I choose a shorter amortization?
If you can afford the higher payment, yes — the interest savings are large. Toggle the term above and compare the "Total interest paid" figure to see the difference for your numbers.

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